Aminoalkyl esters of di- and trihalopyrazole-1-alkanoic and -1-alkenoic acids

ABSTRACT

Certain new aminoalkyl esters of di- and trihalopyrazole-1alkanoic and -1-alkenoic acids have been synthesized. The free bases as well as their acid addition salts and quaternary ammonium salts possess herbicidal and plant growth regulatory activity. The new compounds are prepared and isolated by conventional chemical reactions and procedures. Weed control methods and compositions for herbicidal use are also described.

United States Patent 91,

Kornis et al.

[451 May 20, 1975 AMINOALKYL ESTERS OF DI- ANDTRII-IALOPYRAZOLE-l-ALKANOIC AND -1-ALKENOIC ACIDS [75] Inventors:Gabriel Kornis; Arnolds Steinhards;

Eldon George Nidy;I Ienry J. Vostral, all of Kalamazoo, Mich.

[73] Assignee: The Upjohn Company, Kalamazoo,

Mich.

22 Filed: Aug. 19, 1974 211 App]. No.: 498,478

Related U.S. Application Data [62] Division of Ser.'No. 16,577, March 4,1970, Pat. No.

[52] U.S. Cl 260/310 R; 71/92; 260/243 B;

260/2472 B; 260/268 I-I; 260/293] [51] Int. Cl C07d 49/18 [58] FieldvofSearch 260/310 R [56] References Cited FOREIGN PATENTS OR APPLICATIONS2,037,854 2/1972 Germany OTHER PUBLICATIONS Chemical Abstracts: Vol.76:149909e, (1972); Vol.

76zl22780u, (1972).

Primary Examiner-Albert T.. Meyers Assistant Examiner-Donald B MoyerAttorney, Agent, or Firm-Carl A. Randles, Jr.; Roman Saliwanchik [5 7]ABSTRACT Certain new aminoalkyl esters of diandtrihalopyrazole-l-alkanoic and -1-alkeno'ic acids have been syn- 5Claims, No Drawings AMINOALKYL EST ERS F DI- ANDTRIHALOPYRAZOLE-l-ALKANOIC AND -l-ALKENOIC ACIDS This is a division ofapplication Ser. No. 16,577, filed Mar. 4, 1970, now US. Pat. No.3,849,106.

SUMMARY OF THE INVENTION.

This invention pertains to new'organic compounds, to a process forpreparing the same, to a new method for controlling weeds, and to newherbicidal compositions. The invention is more particularly directed tonew aminoalkyl esters of diand trihalopyrazole-lalkanoic and -l-alkenoicacids, including acid addition and quaternary ammonium salts thereof; toa process for preparing the same; to a new method of controlling weedswith the aminoalkyl esters of this invention; and to new herbicidalcompositions containing the same.

The new aminoalkyl esters of diand trihalopyrazolel-alkanoic and -1alkenoic acids of this invention have the general structural formula:

wherein n is an integer 0, l, 2, or 3; X is a halogen atom; m is theinteger 2 or 3 the halogen atoms being selected independently; R ishydrogen, alkyl of from one to carbon atoms, inclusive, or alkenyl offrom two to 10 carbon atoms, inclusive, the sum of the carbon atoms inthe group being not more than 11; C,.'l-I n' is alkylene of from two toeight carbon atoms, inclusive (n being an integer from 2 to 8,inclusive); and R, and R are individually and collectively defined asfollows:

Individually, R and R are lower-alkyl of from one to eight carbon atoms,inclusive; alkenyl of from three to eight carbon atoms, inclusive;aralkyl of from seven to v13 carbon atoms, inclusive; cycloalkyl of fromthree to eight carbon atoms, inclusive; Cycloalkenyl of from four toeight carbon atoms, inclusive; and

Collectively, the

group is a saturated heterocyclic amino group of from three to sevenring atoms, inclusive, having a total of not more than 15 carbon atoms.

DETAILED DESCRIPTION OF THE INVENTION The foregoing general, structuralformula and definition of variables provide a broad outline of the scope2,3-dimethylpyrrolidinyl,

of this invention. This scope can be more readily recognized byconsideration of some specific variations. Accordingly, some specificlower-alkyl groups of from one to eight carbon atoms, inclusive, are forexample:

methyl, ethyl, propyl, butyl, pentyl, hexyl,.heptyl, octyl', andisomeric forms thereof. Alkyl groups of from one to 10 carbon atoms,inclusive, are those already given, and also nonyl, decyl, and isomericforms thereof.

Some specific alkenyl groups of from three to'eight carbon atoms,inclusive, are for example: allyl, lmethylallyl, Z-methylallyl(methallyl), 2-butenyl (crotyl), 3-butenyl, 1,2-dimethylallyl,3-methyl-2-butenyl, 3-pentenyl, 2,3-dimethyl-2-butenyl, 1,1 ,2-trimethylallyl, 1,3-dimethyl-2-butenyl, l-ethyl-Z- butenyl,4-methyl-2-pentenyl, Z-ethyl-Z-pentenyl, 4,4-dimethyl-2-pentenyl,2-heptenyl, 2-octenyl, 5- octenyl, 1,4-dimethyl-4-hexenyl, and the like.Alkenyl groups of from two to 10 carbon atoms, inclusive, are thosealready given, and also vinyl, 2-nonenyl, 2-. decenyl, and the like.

Some specific aralkyl groups of from seven to 13 carbon atoms,inclusive, are for example: benzyl, phen-. ethyl, l-phenylethyl,Z-phenylpropyl, 4-phenylbutyl, -phenylhexyl, 5-phenyl-2-methylpentyl,benzhydryl, l-naphthylmethyl, 2-( l-naphthyl)ethyl, 2-( 2-naphthyl)ethyl, and the like.

The phrase cycloalkyl of from three to eight carbon atoms, inclusive,includes for example, cyclopropyl, Z-methylcyclopropyl,2,2-dimethylcyclopropyl, 2,3-diethylcyclopropyl, 2-butylcyclopropyl,cyclobutyl, 2-methylcyclobutyl, 3-propylcyclobutyl,2,3,4-trimethylcyclobutyl, cyclopentyl, 2,2-dimethylcyclopentyl,cyclohexyl, 3-methylcyclohexyl, 2,2-dimethylcyclohexyl, cycloheptyl,cyclooctyl, and the like.

Cycloalkenyl groups of from four to eight carbon atoms, inclusive, arefor example, 2-cyclobutenyl, 3- cyclopentenyl, 3-cyclohexenyl,2-ethyl-3-cyclohexenyl, and the like.

The alkylene group C,,, H is preferably one having two or three carbonatoms between the valences, but any branched or straight chain alkylenegroup of from two to eight carbon atoms is satisfactory. The alkylenegroup can-be ethylene, propylene, trimethylene, ethylethylene,tetramethylene, hexamethylene, octamethylene, l-butyltrimethylene, andthe like.

The phrase saturated heterocyclic amino group of from three to sevenatoms, inclusive, having a total of not more than 15 carbon atoms,includes for example, aziridinyl, lower-alkylaziridinyl, for example, 2-methylaziridinyl, Z-ethylaziridinyl, and 2- butylaziridinyl,polylower-alkylaziridinyl, for example, 2,3-dimethylaziridinyl and2,2-dimethylaziridinyl, azetidinyl, lower-alkylazetidinyl, for example,2- methylazetidinyl, 3-methylazetidinyl, and 2- octylazetidinyl,polylower-alkylazetidinyl, for example, 2,2-dimethylazetidinyl,3,3-diethylazetidinyl, 2,4,4-

trimethylazetidinyl, and 2,3,4-trimethylazetidinyl, pyrrolidinyl,lower-alkylpyrrolidinyl, for example, 2- methylpyrrolidinyl,3-butylpyrrolidinyl, and 2-isohexylpyrrolidinyl,polylower-alkylpyrrolidinyl, for example, 2,2-dimethylpyrrolidinyl,2,5-diethylpyrrolidinyl, and 2,3,S-trimethylpyrrolidinyl, piperidino,lower-alkylpiperidino, for example, 2- methylpiperidino,3-methylpiperidino, 4- methylpiperidino, 3-isopropylpiperidino, and4-tertbutylpiperidino, polylower-alkylpiperidino, for example,3,4-diethylpiperidino, 2-methyl-5-ethylpiperidino,

3,5dipentylpiperidino, 2,4,6-trimethylpiperidino, and I2,3,S-triethylpiperidino, hexamethyleneimino,loweralkylhexamethyleneimino, for example, 2- ethylhexamethyleneimino,4-tertbutylhexamethyleneimino, and 3-heptylhexamethyleneimino,polylower-alkylhexamethyleneimino, for example,2,4-dimethylhexamethyleneimino, 3,3-dimethylhexamethyleneimino,2,4,6-tripropylhexamethyleneimino, and 2,2-dibutylhexamethyleneimino,4-lower-alkylpiperazinyl, for example, 4- methylpiperazinyl and4-isopropylpiperazinyl, polylowpounds of Formula I) are convenientlyprepared by reor a second nitrogen atom, the other ring atoms beingcarbon, so that R R as a unit, is alkylene, oxadialkylene,thiadialkylene, or N-alkylazadialkylene, respectively. v I v The newaminoalkyl diand trihalopyrazole-l alkanoates and-l-alkenoates of thisinvention (comacting an acid halide, preferably the chloride, of a di--er-alkylpiperazinyl, for example, 2,2,4,5,5-pentameond nitrogen atom asa ring member. In general, the 7 second hetero atom is preferably in the4-position of a six-membered ring, but it can be in the 3-position. Ac-

' cordingly, referring to the phrase Collectively, the

group is a saturated heterocyclic amino group of from three to sevenring atoms, inclusive, it will be recognized that the R and R chain canbe alkylene, oxadialkylene, e.g.,

Accordingly, a further definition of the phrase is:

Collectively, R and R taken as a unit with the -N atom, are saturatedheterocyclic amino groups of from three to seven ring atoms, inclusive,each group having a total of not more than carbon atoms, one of the ringatoms being selected from carbon, oxygen, sulfur,

or trihalopyrazole-l-alkanoic or -l-alkenoic acid having the structuralformula:

wherein n, X, m and R are as previously defined, with anN,N-disubstituted aminoalkanol having the structural formula:

- 1 HO-C ,H ,N 111 I v In 2nwherein C" I H R and R are as previouslythiadialkylene,

a 1-, or N-alkylazadialkylene, e.g., ll-(:3-

This reaction is preferably effected at a temperature between about 50and C. in the presence of an inert organic reaction medium and an acidbinding agent. If desired, an excess of the aminoalkanol reactant can beused to bind the hydrogen halide released by the esterification, or atertiary amine such as triethylamine, pyridine, picoline or the like canbe used. Representative suitable inert organic reaction media includetoluene (preferred), benzene, xylene, and the like.

Alternatively, the new aminoalkyl diand trihalopyrazolel-alkanoates and-l-alkenoates of Formula I can be prepared by reacting a diortrihalopyrazole-l-alkanoic or -l-alkenoic acid (Formula ll) with anN,N-disubstituted aminoalkanol (Formula III) in the presence of an inertorganic reaction medium of the kind mentioned above. Conveniently, theesterification is accomplished by heating the acid and the aminoalkanolat a temperature of about 100 to 125 C., in the presence of a catalyst,for example, p-toluenesulfonic acid, azeotroping the water formed by thereaction, and recovering the basic ester according to conventionalmethods.

Representative N,N-disubstituted aminoalkanols includeZ-(dimethylamino)ethanol, 2- (diethylamino)ethanol,2-(dipropylamino)ethanol, 2- dibuty1amino)ethanol, 2-diethylamino-1-methylethanol, 3-diethylamino-l-propanol, 4- diethylamino-l-butanol,2-morpholinoethanol, 2- piperidinoethanol, 2-pyrrolidinoethanol,8-hexamethyleneiminol -octanol, 2-( 4- methylpiperazino )ethanol,3-thiomorpholino-1- propanol, 2-(diallylamino)ethanol, 2-(dicyclohexylamino )ethanol, S-methylbenzylamino- 1- pentanol, and thelike. I

Acid halides of the above Formula 11 diand trihalopyrazole-l-alkanoicand -1-alkenoic acids can be prepared by means commonly used forconverting carboxylic acids to their acid halides, for example, byreaction of an acid with thionyl chloride.

The diand trihalopyrazole-l-alkanoic and -1- alkenoic acids of Formula11 are prepared from their alkyl esters, preferably methyl or ethylesters, by conventional alkaline hydrolysis. If desired, the alkyl diortrihalopyrazole-l-alkanoate or -l-alkenoate is hydrolyzed with an alkalimetal hydroxide in the reactionmixture in which it is formed, and thealkanoic or alkenoic acid is recovered by adding strong acid toneutralize the base and to precipitate the desired diortrihalopyrazolel-alkanoic or -l-alkenoic acid of Formula II.

The alkyl diand trihalopyrazole-l-alkanoates and -1-alkenoates, i.e.,alkyl esters of Formula II alkanoic and alkenoic acids, are prepared byreacting an alkali metal salt (preferably a sodium or potassium salt) ofa dior trihalopyrazole with an alkyl haloalkanoate or haloalkenoate. Arepresentative formula of suitable alkyl haloalkanoates andhaloalkenoates is as follows:

0 H 1 l R-(;.-C l1 0-a ky wherein n and R are as previously defined, Xis chlorine, bromine, or iodine, and alkyl preferably is methyl orethyl.

In accordance with a preferred process, the diandtrihalopyrazole-l-alkanoic and -l-alkenoic acids of Formula II areprepared by first reacting a dior trihalopyrazole with an alkylhaloalkanoate or haloalkenoate (according to Formula IV) in the presenceof an alkali metal carbonate such as potassium carbonate or sodiumcarbonate and acetone, and then hydrolyzing the thus-produced ester tothe corresponding acid.

The di-or trihalopyrazole is dissolved in acetone and a solid anhydrousalkali metal carbonate is added. The mixture is heated for a fewminutes, then cooled, and the alkyl haloalkanoate or haloalkenoate isadded. After further heating at the reflux temperature and cooling.aqueous alkali metal hydroxide is added, the

alkanoates and -l-alkenoates of this invention are represented inFormula I, above, in the free base form. Those skilled in the art,however, will note that the amino group can associate with the hydrogenions of a dissociated acid to form stable acid addition salts. Hence,the stable acid addition salts are contemplated .as an embodiment of theinvention. The acid addition salts of this invention are in generalcrystalline solids, are readily prepared, and area convenient form ofthe new compounds for many purposes. The free base, new compounds alsoform quaternary ammonium salts.

All forms, i.e., the free base form, the acid addition salt form, andthe quaternary ammonium salt form are useful as herbicides and plantgrowth regulants in accordance with the invention.

The acid addition salts embodiment of the compounds of this inventionaffords a convenient means of obtaining the free base compounds in pureform. The pure free base compounds can be obtained from an acid additionsalt by neutralizing the acid with a base and recovering the free baseaccording to conventional methods. Likewise, the acid addition salts ofthe invention are convenient means of obtaining the compounds incrystalline form, and for minimizing decomposition of the free bases.

Acid addition salts are also a convenient form of the compounds of theinvention for assuring solubility in aqueous media. This quality of theacid addition salts can be an especially important factor in theherbicidal method of this invention. All acid addition salts are usefulas herbicides as long as the acid anion does not interfere with thedesired herbicidal effect of the free base.

The hydrochlorides of the compounds of Formula 1 are representative,readily prepared and preferred acid addition salts according to theinvention. The hydrochlorides are obtained by using hydrochloric acid oranhydrous hydrogen chloride. Other representative mineral acid additionsalts are the hydrobromides, the hydroiodides, the sulfates, thephosphates, the hexafluorophosphates, the nitrates, thetrichloroacetates, the arsenates and the fluosilicates. Representativeorganic acid addition salts are the acetates, the propionates, thebenzoates, the salicylates, the glycolates, the

succinates, the nicotinates, the tartrates, the maleates,

the malates, the oxalates, the pamoates, the methane.- sulfonates, thedodecylbenzenesulfonates, the arsanilates, the picrates, and thelactates.

The fluosilicic acid addition salts of the aminoalkyl di andtrihalopyrazole-l-alkanoates of this invention are useful asmothproofing agents in accordance with US. Pat. Nos. 1,915,334 and2,075,359. The thiocyanic acid addition salts are useful for condensingwith formaldehyde in accordance with US. Pat. Nos. 2,425,320 and2,606,155 to form amine thiocyanateformaldehyde condensation productsfor use as. pickling inhibitors.

The'quaternary ammonium salts embodiment of the compounds of thisinvention are obtained by reacting the free base with organic esters ofacids such as hydrohalic acids. Representative organic esters includetribromopyrazole- 1 -propionate,

trative of the process and products of the present invention but are notto be construed as limiting.

PREPARATION 1 Preparation of Ethyl 3 ,4,5-Tribromopyrazole- 1 -acetate Aquantity (92 gm., 0.3 mole) 3,4,5- tribromopyrazole was added withvigorous stirring to a solution of 7.1 gm. sodium (0.31 mole) in 300 ml.absolute ethanol. After the mixing was complete, 100 gm.

(0.6 mole) ethyl bromoacetate was added dropwise wise while stirring wascontinued. The mixture was diluted with 200 ml. absolute ethanol andthis reaction mixture was stirred at about C. for about 18 hours. Afterremoving most of the ethanol by evaporation '8 tate formed. Theprecipitate was collected on a filter and recrystallized from a mixtureof ether and technical hexane. There was thus obtained 101 gm. 3,4,5-tribromopyrazole-l-propionic acid having a melting point at 112 to 113C.

. Analysis: I

under reduced pressure, 100 m1. 6 N hydrochloric acid was added to theresidue, and this aqueous acid mixture was made alkaline with solidsodium carbonate. The aqueous layer was separated and extracted withthree 60-m1. portions of ether. The ether extracts were combined, washedwith three -'ml. portions of water, and dried with anhydrous magnesiumsulfate. After removing the ether by evaporation under reduced pressure,there was obtained a white solid. Recrystallization from technicalhexane (Skellysolve B, a mixture of isomeric hexanes having a boilingrange between 61 C. and 69 C.) gave 96.0 gm. of ethyl3,4,5-tribromopyrazolelacetate having a melting point at 101 to 103 C.

Analysis:

Calcd. for C H Br N O C, 21.51; H, 1.81; N, 7.17; Br, 61.33. Found: C,21.79; H, 1.62; N, 6.96; Br, 61.56.

Following the same procedure, but substituting methyl 2-bromopropionate,ethyl 3-bromopropionate, ethyl 4-bromobutyrate, ethyl 2-bromohexanoate,ethyl 2-bromooctanoate, ethyl 2.-bromodecan0ate, ethyl 2-bromododecanoate, ethyl 2-bromo-4- methylpentanoate and ethyl2-bromo-9-dodecylenate for ethyl bromoacetate, there are prepared:methyl 3,4- ,5-tribromo-a-methylpyrazole-l-acetate, ethyl 3,4,5- ethyl3,4,5-tribromopyrazole-l-butyrate, ethyl3,4,5-tribromo-abutylpyrazole-l-acetate, ethyl3,4,5-tribromo-a-hexylpyrazole- 1 -acetate, ethyl 3,4,5-tribromo-aoctylpyrazole- 1, -acetate, ethyl 3,4,5-tribromo-ozdecylpyrazole- 1 -acetate, ethyl 3,4,5-tribromo-aisobutylpyrazole-l-acetate, and ethyl 3,4,5-tribromo-a-(7-decenyl)pyrazole-l-acetate, respectively.

PREPARATION 2 Preparation of 3,4,5-Tribromopyrazole-l-propionic acid Amixture consisting of 9.1 gm. (0.03 mole) 3,4,5- tribromopyrazole and8.1 gm. (0.045 mole) ethyl 3- 'bromopropionate was heated at 140 C. for24 hrs. in

Calcd. for C H Br N O z C, 19.12; H, l.

33 .4 Br, 63.61. Found: C, 19.31; H, 1.54;

3 .44;v Br, 64.05.

Following the same procedure, but substituting 3,5- dichloropyrazole,3,4,5-triiodopyrazole, dibromopyrazole, and 3,5-dibromo-4-chloropyrazolefor 3,4,5-tribromopyrazole, there are prepared the corresponding:3,5-dichloropyrazole-l-propionic acid, 3,- 4,5-triiodopyrazole- 1-propionic acid, 3 ,4- dibromopyrazole-l-propionic acid, and3,5-,dibromo-4- chloropyrazole- 1 -propionic acid, respectively.

PREPARATION 3 Preparation of 3,4,5-Tribromopyrazole-l-acetic acidAnalysis: 7

Calc'd. for C H Br N O C, 16. H, .72; Br, 66.08. .81; Br, 65.88.

PREPARATION 4 Preparation of Ethyl 3,4,5-Tribromo-amethylpyrazole- 1-acetate Following the procedure of Preparation 1, but substitutingethyl 2-bromopropionate for ethyl bromoacetate, there was prepared ethyl3,4,5-tribromo-amethylpyrazole1-acetate having a melting point at 64 to66 C.

Analysis:

Calcd. for C H Br N O C, 23.73; H, 2.24; N, 6.92; Br, 59.21. Found: C,23.83; H, 2.55; N, 6.98; Br, 59.07.

PREPARATION 5 tuting ethyl 2-bromobutyrate for ethyl 2- bromopropionate,there was prepared 3,4,5-tribromo- Analysis; a-ethylpyrazole-l-aceticacid having a melting point at Ted. for c n sr N o t 98 to 100 C.

C, 19.12; H, 1.34; N, 7.43; Br, 63.6l. Found: C, 19.27; H. 1.45; N,7.34; Br, 63.74. 5

Analysis:

Cld.f CHB NO- z PREPARATION 6 ac or c:2 1.51; 1-1, 1.81; N, 7.17; Br,61.33. Preparation of 3,4,5-Tribromopyrazole-l-butyric acid Fmmd: C121;H; 169? N 6-86? Following the procedure of Preparation 2, butsubstitutlng ethyl 4-bromobutyrate for ethyl 3 PREPARATION 10bromopropionate, there was prepared 3,4,5-tr1- bromopyrazole-l-butyricacid having a melting point at Preparatlon 0f -l pr pylpyrazolel l28.5to 130 C. acetic acid v Following the same procedure as Preparation 8,but substituting ethyl 2-bromo-3-methylbutyrate for ethyl2-bromopropionate, there was prepared 3,4,5-

f tribromo-a-isopropylpyrazolel-acetic acid having a die dgf z i i jiqtm; N. 7.17; Br, 01.33. melting Point at 920 to 950 Found: C. 21.98:H.'l. 8', N, 7.26; Br, 61.45.

Analysis: 7 PREPARATION 7 Calcd. for ciH BriN-ioa: Y 2 2' .2 Pollowmgthe procedure of Preparation 2, but substi- Found; 22.; 3;: tutmg ethyl2-bromo-3-butenoate and ethyl 3-bromo-2- methylpropionate for ethyl3-bromopropionate, there are Prepared PREPARATI3,4,5-tribromo-a-vinylpyrazole-l-acetic acid and ON 113,4,5-tribromo-a-methylpyrazole l-pr0pionic acid, p a g of -T r y pyrespectively. acetlc acid,

Following the same procedure as Preparation 8, but PREPARATION 8substituting ethyl 2-bromohexanoate for ethyl 2- Preparation of3,4,5-Tribromo-a-methylpyrazole- 3 bromopl'oplonatei there was p lq if 1acetic acid 5 a-butylpyrazole-l-acetic acid having a meltmg po1nt at Aquantity 3.04 gm., 0.01 mole) of 345 tribromopyrazole was dissolved in70 ml. acetone and 2.76 gm. (0.02 mole) solid anhydrous potassiumcarbonate was added. The mixture was heated at the reflux 40 Analysis:temperature with stirring for 10 minutes and, after Q' for gdgi ig a 65N 669 B 57 2} Cooling 2' (0-011 mole) ethyl Found: c: 2593; HI 21791 NI6.58; Bi, 5713i: bromoproplonate was added. This reaction mixture washeated at the reflux temperature for 1 /2 hrs. After cooling, an aqueoussolution of sodium hydroxide (0.5 gm. in 90 ml. water) was added. Theacetone was dis- PREPARATION l2 tilled off and the remaining aqueoussolution was Preparation of Ethyl y py heated at the reflux temperaturefor-2 hrs. The clear so-' lacetate lution thus obtained was cooled andacidified to about A q y gof 5- H 2 i h 2 N hydrochloric i A whiteprecipitate tribromopyrazole was dissolved n 500 ml. acetone and thatformed was collected on a filter, washed with wamole) sohfi anhydrousPotasslum Carbon ter, and dried. There was thus obtained 3.55 gm. 95%ate was added; m1xture WaSfieated at the reflux yield) of 3,4,5 tribmm0a methy]pyra2o1e 1 acetic temperature w1th stirring for 10 m1nutes andafter coolacid having a melting point at 162 to 164C, identical mg ethylz-bmmc'hexamate was with the product of Preparation added. Th1s reactionm1xture was heated at the reflux temperature for 1 /2 hrs., cooled, andthen filtered. The

solids on the filter were washed with acetone and the combined acetonefiltrate and acetone washes were Analysis evaporated to dryness underreduced pressure. Distilla- Calcd for t r a a r tion of the residueyielded ethyl 3,4,5-tribromo-ar 1355 Zfif 3: butylpyrazole-l-acetate,41.0,g. (92% yield), having a boiling point at 138 to 140 C. at 0.15 mm.mercury pressure.

PREPARATION 9 Preparation of 3,4,5-Tribromo-a-ethylpyrazole-l- Analysis;acetic acid Calc'd. for c,,1-1, r N o N 627 B C, 29.55; H. 53.64.Followlng the procedure of Preparatlon 8, but substl Found: C, 2993; H367; N, 613; 53.95

PREPARATION 13 Preparation of Ethyl3,4,5-Tribromo-a-ethylpyrazolel-acetate Following the same procedure asPreparation 12, but substituting ethyl 2-bromobutyrate for ethyl 2-bromohexanoate, there was prepared ethyl 3,4,5-

tribromo-a-ethylpyrazolel -acetate.

Analysis:

Calcd. for C H Br N O C. 25.80; H. 2.65; N. 6.69; Br. 57.23. Found: C,26.35; H. 2.88; N, 6.63; Br. 57.04.

PREPARATION 14 Preparation of Ethyl 3,4,5-Tribromo-d-isopropylpyrazole-1 -acetate Following the same procedure as Preparation 12, but

substituting ethyl 2-bromo-3-methylbutyrate for ethyl 2-bromohexanoate,there was prepared ethyl 3,4,5 tribromo-a-isopropylpyrazole-l-acetatehaving a boiling point at 1 19 C. at 0.05 mm. mercury pressure.

PREPARATION Preparation of 3,5-Dibromopyrazole- 1 -ethanol A solution of9.7 g. (0.025 mole) ethyl 3,4,5- tribromopyrazole-l-acetate in 125 ml.dry ether was mixed with a suspension of 1.9 g. (0.05 mole) lithiumaluminum hydride in 50 ml. dry ether. The reaction mixture was heated atthe reflux temperature for two hrs. and then cooled. Ethyl acetate (5ml.) and then water (30 ml.) were added and after settling the etherPREPARATION 17 went into solution. The aqueous solution was extractedwith three 50-ml. portions of ether and the combined ether extracts werewashed with water and dried over anhydrous sodium sulfate. Evaporationof the ether under reduced pressure followed by chromatography on silicagel using the solvent system benzene, 85 :chloreform, 10: glacial aceticacid, 5 (by volume) gave a solid which on recrystallization fromacetone-hexane gave 3,5-dibromo-a-methylpyrazole-l-acetic acid having amelting point at 124.5 to 126 C.

portion was decanted. The ether solution was washed with two -ml.portions of water and dried over anhydrous sodium sulfate. Afterremoving the ether by evaporation, the oily residue was treated withdecolorizing charcoal and crystallized from a mixture of ethyl ether andpetroleum ether (boiling at the temperature range 30 C. to 60 C.). Therewas thus obtained 6.5 gms. (75% yield) of 3,5-dibromopyrazole-l-ethanolhaving a melting point of 64 to 66 C.

Analysis:

Calcd. for C H Br- N O:

C, 22.24: H, 2.24; N, 10.37; Br. 59.20. Found: C, 22.63; H. 2.45; N.10.52; Br, 59.01.

PREPARATION 16 ethanol having a melting point at 835 to 845C.

Analysis:

Calcd. for C H Br N O:

C, 2 8; H, 2.84; N. 9.87; Br. 56.28. Found: C, 25.53; H. 2.92; N 9.65;Br, 55.85.

Analysis:

Calc'd. for C H Br N O C, 24.18; H, 2.03; N, 9.40; Br. 53.64. Found: C,23.98; H. 2.06; N, 9.63; Br. 53.97.

Following the same procedure, but substituting 3,5- dibromopyrazole- 1-ethanol for 3 ,5 -dibromo-amethylpyrazole-l-ethanol, there is prepared3,5- dibromopyrazole- 1 -acetic acid.

EXAMPLE 1 Preparation of 2-(diethylamino)ethyl3,4,5-tribromopyrazole-l-acetate and hydrochloride thereof A mixture of3,4,5-tribromopyrazole-l-acetic acid (12.4 gm., 0.034 mole) and thionylchloride (10 ml.) was heated at the reflux temperature for 3 hrs.,followed by removal of excess thionyl chloride under reduced pressure.An aliquot (0.0204 mole) of the resulting3,4,5-tribromopyrazole-l-acetyl chloride in 60 ml. toluene was addeddropwise during 30 min. to a solution of 2(diethylamino)ethanol (0.0204mole) in 100 ml. toluene. The mixture was heated at the refluxtemperature for 30 min. and was then cooled, filtered, and dried. The2-(diethylamino)ethyl 3,4,5- tribromopyrazole-l-acetate hydrochloridethus obtained weighed 8.5 g. yield) and had a melting point at 166.5 to168.5 C. The compound after recrystallization from a mixture ofchloroform and technical hexane had a melting point at 170.5" to 171 C.

Analysis:

Calc'd. for C,,H .,Br N=,O .HCl:

C. 26.50; H, 3.43; N. 8.43. Found: C. 26.66; H. 3.61; N, 8.39.

2-( Diethylamino)ethy1 3 ,4 ,5 -tribromopyrazolel-acetate is obtained byneutralizing an aqueous-solu- EXAMPLE 2 Preparation of2-(diethylamino)ethyl 3 ,4,5-tribromo-a-m ethylpyrazolel -acetate andsaltsthereof Following the procedure of Example 1, but substituting3,4,5-tribromo-a-methylpyrazole-l-acetic acid for3,4,5-tribromopyrazolel-acetic acid, there was obtained 2-(diethylamino)ethyl 3 ,4,5-tribromo-amethylpyrazole-l-acetate hydrochloride whichafter recrystallization from a mixture of acetone and hexane had amelting point at 142 to 144 C.

2-(Diethylamino)ethyl 3,4,5-tribromo-amethylpyrazole- 1 -acetate isobtained by neutralizing an aqueous solution of the above hydrochloridewith aqueous sodium carbonate solution, extracting the mix-.

EXAMPLE 3 Preparation of 2-(diethy1amino)ethyl 3,4,5-tribromo-a-methylpyrazolel -acetate methiodide A solution of 2-(diethylamino)ethyl 3,4,5-tribromooz-methylpyrazole-l-acetate (0.2 mole)in diethyl ether (75 ml.) is treated with methyl iodide (0.4 mole) andleft standing at room temperature for several days. The resultingprecipitate is filtered and dried. There is thus obtained2-(diethylomino)ethyl 3,4,5-tribromo-amethylpyrazole-l-acetatemethiodide.

Similarly, but replacing methyl iodide with ethyl bromide, propylchloride, benzyl chloride and allyl bromide, there areobtained2-(diethylamino)ethyl 3,4,5- tribromo-a-methylpyazole-1-acetateethobromide, propyl chloride, benzyl chloride and allyl bromide,respectively. V

,EXAMPLE4 Following the procedure of Example 1, butsubstituting2-(dimethylamino)ethanol, 2-

(dipropylamino)ethanol, 2-(dibutylamino )ethanol, 2-

diethylaminol-methylethanol, 3-diethylamino-1- propanol,4-diethy1amino-1-butanol, 2- morpholinoethanol, 2-piperidinoethanol, 2-pyrrolidinoethanol, 2-(4-methylpiperazino)ethanol,

8-hexamethyleneiminol -octanol, 3-thiomorpho1inol I propanol,"-(dicyclohexylamino)ethanol 2-(diallylamino)ethanol, 2- I andS-methylbenzylamino-l-pentanol for 2-(diethylamino)ethanol, there areprepared, the 2-(dimethylamino)ethyl, 2,- (dipropylamino)ethyl,2-(dibutylamino)ethyl, 2-diethylamino-l-methylethyl,3-(diethylamino)propyl, 4- (diethylamino)butyl, 2-morpholinoethyl, 2-piperidinoethyl, 2-pyrrolidinoethyl, 2-(4- methylpiperazino)ethyl,8-hexamethyleneiminooctyl, 3-thiomorpholinopropyl,2-(diallylamino)ethyl, 2- (dicyclohexylamino)ethyl and 5-(methylbenzylamino)- pentyl esters, respectively, of3,4,5-tribromo-a-methyl pyrazole-l-acetic acid, first as thehydrochlorides and then as the free bases.

EXAMPLE 5 Following the procedure of Example 1, but substitutmg 3,4,5-tribromopyrazolel -propionic acid,

3 ,4,5-tribromopyrazolel -butyric acid,

3 ,4,5-tribromo-a-vinylpyrazolel-acetic acid,

3 ,4,5-tribromo-a-methylpyrazole- 1 -propionic acid,

3 ,4,5-tribromo-oc-ethylpyrazole-1-acetic acid,

3,4,5-tribromo-a-isopropylpyrazole- 1 -acetic acid,

3 ,5-dibromo-a-methylpyrazolel -acetic acid,

3,5-dichloropyrazole- 1 -propionic acid,

3 ,4,5-triiodopyrazole- 1 -propionic acid,

3,4-dibromopyrazolel -propionic acid, and

3 ,5-dibromo-4-chl0ropyrazo1e 1-propionic acid for3,4,5-tribromopyrazole-l-acetic acid, there are prepared the2-(diethylamino)ethyl esters of the respective acids, first as thehydrochlorides and then as the free bases. I The new aminoalkyl estersof diand trihalopyrazolel-alkanoic and -1-alkenoic acids of thisinvention (compounds of Formula I) have been found to be active asherbicides and plant growth regulators. The new compounds can be used toprevent damage to field crops due to weed competition, and they can beused to prevent unsightly and deleterious growths of weeds on homelawns, golf courses, cemeteries, railroad rights-of way, and parks.

Compounds of this invention have been found to be highly active againstboth broadleaf and grassy weeds, with some variations between onecompound and another within the series. lllustratively, 2-(diethylamino)ethyl ester of 3,4,5-tribromopyrazole-1- acetic acid and2-(diethylamino)ethyl ester of 3,4,5- tribromo-a-methylpyrazole-l-aceticacid are especially active against various weeds, e.g., crabgrass(Digitaria sanguinalis L.), yellow foxt'ail (Setaria glauca L.), wildoats (Avena fatua L.), bindweed (Convolvulus arvensis L.), Johnson grass(Sorghum halepense L.), buckhorn plantain (Plantago lanceolata L.),curly dock (Rumex crispus L.), wild mustard (Brassica kaber DG.),purslane (Portulaca oleracea L.), and barnyard-grass (Echinochloacrusgalli L.).

ll1ustratively,'control and significant growth retardation of theforegoing weed species has been achieved using the named compounds andother specific compounds of this invention at rates of from 1 to 12.5lbs. per acre. Depending upon the kinds of weeds to be controlled, thestage of weed development, the degree of infestation, and the presenceor absence of aesthetic or crop plants, the compounds of this inventioncan be applied to soil, germinating weed seeds, weed seedlings, plantgrowth media, growing plants, or any other selected situs for control ofweeds at rates ranging from about one-fourth to one-half lb. per acre upto about 50 lbs. per acre. Ordinarily, the situs will be soil, but thisterm 'is used in the broad sense anywhere where form with a homogeneousdispersible carrier. Adjuvants such as surfactants, humectants,dispersants, adhesive or sticking agents, corrosion inhibitors, .andantifoaming agents can be included.

A homogeneous dispersible carrier comprehends a particulate solidcarrier or a liquid carrier diluent. The compound can be dispersed in aliquid carrier diluent as a solute or as finely divided particles(suspension).

The term dispersible, as used in this specification and in the claims,means matter in a liquid or particulate state such that it can be evenlydistributed over a given area or metered into a body of water. A liquid"state includes true solutions as well as dispersions of particulatesolids in a liquid. Emulsions of one liquid in another, e.g.,oil-in-water, are also contemplated. The active compound can be ineither the dispersed phase, the continuous phase, or partitioned betweenthem both. In general, the active compound will be preponderantly in thedispersed phase when emulsions are used. A particulate state includesthegeneral concept of finely divided separate particles, and granularparticles as large as 10 mesh (US) .or even somewhat larger whenappropriate herbicidal practice indicates an advantage in using largergranules.

The granular particles could be included in what is termed aninterstitial state, which contemplates the deposition or entrapment ofthe active compound within the interstices of a porous body. Forexample, the compounds can be mixed with an elastomer, e.g., naturalrubber, chloroprene, butyl rubber, polyether and polyester urethanes andthe like, which may be further processed according to conventionaltechniques in the elastomeric art. The latter elastomeric matrices aswell as conventional granules provide a slow, sustained release of theactive herbicide so that herbicidal concentrations of the activecompound can be obtained over a prolonged interval for the control ofweeds.

Illustrative of the adjuvants named above, humectants include glycerol,diethylene glycol, solubilized lig-.

laurate, polyalkylether condensates of fatty acids, lig-' ninsulfonates, and the like. The preferred class of surfactants includesblends of sulfonated oils and polyal-' coho] carboxylic acid esters(Emcol H-77), blends of polyoxyethylene ethers and oil-solublesulfonates (Emcol l-l-400), blends of alkyl aryl sulfonates andalkylphenoxy polyethoxy ethanols (Tritons X-l5l, X- I 16 1, and X-l71),e.g., about equal parts of sodium kerylbenzene sulfonate andisooctylphenoxy polyethoxy ethanol containing about l2 ethoxy groups,and blends -of calcium alkyl aryl sulfonates and polyethoxylated'vegetable oils (Agrimul N 8). It will be understood, of course, that thesulfate and sulfonate surfactants suggested above will preferably beused in the form of their soluble salts, for example, .their sodiumsalts. All of these surfactants are capable of reducing the surfacetension of water to less than about 40 dynes per centimeter inconcentrations of about 1% or less. The dispersible powder formulationscan be prepared with a mixture of surfactants of the types indicated ifdesired.

The concentration of the active compound, a new aminoalkyl ester of adior trihalopyrazole-l-alkanoic or -l-alkenoic acids according to thisinvention, in the hew herbicidal formulations of this invention is notusution, and the thoroughness of coverage desired. The

total amount to be applied depends upon' the kinds of weeds and crop, ifany, the severity of infestation, the

stage of plant development, and the season of the year.

sulfates, polyoxyethylene-sorbitan Representative homogeneousdispersible formulations according to this invention include sprays,dusts, and granular formulations. Sprayformulations are preferred forfoliar applications and for uniformly controlled applications to a soil.Granular formulations are usually applied in bands spanning the seededrow, although broadcast distribution is advantageous when soilincorporation is practiced and a prolonged effect is desired.

The spray formulations in accordance with the invention can be aqueoussolutions, aqueous suspension, water-in-oil emulsions, oil-in-wateremulsions, and oil solutions The spray formulations will convenientlycomprise from about 0.1% or lower to about 50% by weight or even higher,a volume of spray being applied so that.

a herbicidally effective amount of aminoalkyl esters of diandtrihalopyrazole-l-alkanoic and -l-alkenoic acids is distributed over thetreated area. Sprays containing about 0.25 ounce to about l6.lbs. ofaminoalkyl esters of diand trihalopyrazole-l alkanoic and -1- alkenoicacids in a 20 gal. to 40 gal. volume are applied to foliage or soil foreffective herbicidal action.

Concentrates for preparing spray formulations are advantageouslyprepared by dissolving-the active compounds of the invention in asolvent, or by dispersing. the active compounds in a dispersible solidor liquid ethyl ketone,'dimethylformamide, alcohols, monoalkyl ethers ofethylene glycol, ethyl acetate, and the like. Representativesubstantially water-immiscible organic liquids (i.e., a solvent carrierwhich is soluble'in water to the extent of less than 2.5% by volume attemperaturesof theorder of 20 to 30 C.) for preparing 'emul sifiableconcentrates include petroleum oils, distillates, toluene, xylenecumene, and like aromatic hydrocarbons, isoparaffin oilgmineral oil, andthe like.

Advantageously, the concentration of active ingredient in theemulsifiable concentrates (with or without surfactant) can range fromabout to about 50% by weight, preferably from about to about 40%. -Aconcentrate comprising 20% (by weight.) of the compound dissolved in awater-immiscible solvent of the kind noted above can be admixed with anaqueous medium in the proportions of 13 ml. of concentrate with 1 gal.of medium to give a mixture'containing 700'parts of active ingredientper million parts of liquid carrier. Similarly, 1 qt. of a 20%concentrate mixed with 40 gals. of water provides about 1,200 ppm (partsper million) of active ingredient. In the same manner, more concentratedsolutions of active ingredient can be prepared.

Dust formulations in accordance with the invention are readily preparedby dispersing the active compound in a dispersible solid by grinding amixture of the compound and a pulverulent solid carrier in the presenceof each other. Grinding is conveniently accomplished in a ball mill, ahammermill, or by air-blast micronization. These dust compositions canalso be prepared by dissolving the aminoalkyl esters of diandtrihalopyrazolol-alkanoic and -l-alkenoic acids in a volatile solventsuch as methylene chloride, mixing the solution with a pulverulent solidcarrier, evaporating the solvent, and pulverizing the impregnatedcarrier. A suitable ultimate particle size is less than 60 microns.Preferably, 95% of the particles are less than 50 microns, and about 75%are 5 to 20 microns. Dusts of this degree of comminution areconveniently free-flowing. Dusts are particularly adapted for air-borneapplication over ponds, lakes, marshes, swamps, swales, and potholes.

Representative suitable pulverulent solid carriers in-- clude thenatural clays such as China, Georgia, Barden, attapulgus, kaolin, andbentonite clays; minerals in their natural forms as they are obtainedfrom the earth such as talc, pyrophyllite, quartz, diatomaceous earth,fullers earth, chalk, rock phosphates and sulfates, calcium carbonates,sulfur, silica and silicates; chemically modified minerals such aswashed bentonite, precipitated calcium phosphate, precipitated calciumcarbonate, precipitated calcium silicate, synthetic magnesium silicate,and colloidal silica; and organic flours such as wood, walnut shell,soybean, cottonseed, and tobacco flours, and free-flowing, hydrophobicstarches.

The proportions of pulverulent carrier and aminoal kyl esters of diandtrihalopyrazole-l-alkanoic and -lalkenoic acids can vary over a widerange depending upon the plants to be controlled, rates of applicationaccording to equipment available, and the conditions of treatment. Ingeneral, dust formulations can contain up to about 90% (on a weightbasis) of the active ingredient. Dusts having as little as 0.001% of theactive ingredient can be used, but a generally preferred proportion isfrom about 0.50% to about 20% of active ingredient.

Advantageously, a dust formulation as described above includes asurfactant, because about 0.1% to about 12% of a surfactant promotesdispersibility of a dust in water and facilitates formulation of aqueoussprays of dispersibility of a dust formulation applied directly to watersurfaces or aquatic weeds. Dust formulations comprising a surfactantareknown as dispersible or wettable powders. As indicated, dispersibleor wettable powders can be admixed with water to obtain any desiredconcentration of active ingredient. The dispersible or wettable powderscan conveniently comprise from about 10% to about active ingredient.preferably about 30% to about 80%.

A suitable dispersible powder formulation is obtained by blending andmilling 327 lbs. of Georgia .Clay. 4.5 lbs. of isooctylphenoxypolyethoxy ethanol (Triton X- as a wetting agent, 9 lbs. ofa polymerizedsodium salt of substituted benzoid long-chain sulfonic acid (Daxad 27)as a dispersing agent, and 113 lbs. of the active ingredient. Theresulting formulation has the following percentage composition (partsherein are by weight unless otherwise specified):

Active ingredient 25% isooctylphenoxy polyethoxy ethanol 1% Polymerizedsodium salt of substituted benzoid long-chain sulfonic acid 2% GeorgiaClay 72% This formulation, when dispersed in water at the rate of 10lbs. per 100 gals, gives a spray formulation containing about 0.3%(3,000 ppm) active ingredient which can be applied to weeds at the rateof 40 gals. per acre to give a total application of active ingredient of1 lb. per acre.

The new aminoalkyl esters of diand trihalopyrazolel-alkanoic and-l-alkenoic acids of this invention, more particularly,2-(diethylamino)ethyl ester of 3,4,5- tribromopyrazole l-acetic acid,possess advantageous plant growth regulatory activity and they modifythe normal apical dominance and produce symptoms of epinasty whenapplied to growing plants. They can be used to promote lateral budgrowth and increased numbers of fruiting bodies.

Further in accordance with this invention, certain formulations of thenew aminoalkyl esters of diand trihalopyrazole-l-alkanoic and-l-alkenoic acids of this invention with oil are particularlyefficacious, and herbicidal action of the compound is improved. Anypetroleum oil can be used so long as it is not so viscous as to be toodifficult to disperse. A non-phytotoxic oil is satisfactory.

Advantageously, a 50% wettable powder of the herbicidal activeingredientis mixed with about 38 gals. water and 2 gals. oil for sprayapplication. Alternatively, about 2 gals. oil and a 50% wettable powderare premixed and then dispersed in about 38 gals. water for 5 sprayapplication-1n field tests, oil formulations of the foregoing type havegiven improved herbicidal action.

We claim: 1. A compound of the formula:

wherein n is an integer 0, l, 2, or 3; X is a bromine, atom; m is theinteger 3, R is hydrogen, alkyl of from one to carbon atoms, inclusive,or alkenyl of from two to 10 carbon atoms, inclusive, the sum of thecarbon atoms in the group H fi n zrf being not more than 1 l; C, H2" isalkylene of according to claim 1.

1. A COMPOUND OF THE FORMULA:
 2. The compound 2-(diethylamino)ethyl3,4,5-tribromopyrazole-1-acetate according to claim
 1. 3. The compound2-(diethylamino)ethyl 3,4,5-tribromo- Alpha -methylpyrazole-1-acetateaccording to claim
 1. 4. The compound 2-(diethylamino)ethyl3,4,5-tribromopyrazole-1-acetate hydrochloride according to claim
 1. 5.The compound 2-(diethylamino)ethyl 3,4,5-tribromo- Alpha-methylpyrazole-1-acetate hydrochloride according to claim 1.